On top of the already understood effects of a stroke, a new study has found that the stroke impairs a patient's memory, slowing thinking speed while aging the brain by almost eight years.

Researchers from the University of Michigan analyzed national data from more than 4,900 black and white Americans, aged 65 and older, who underwent memory tests and thinking speed tests between 1998 and 2012.

The results, published in the July issue of the journal Stroke, showed that patients who suffered a stroke tested as if they had suddenly aged 7.9 years. The study found that a stroke also had similar results across both races. However, previous research found that the rates of memory and thinking problems in older blacks were generally twice that of whites.

Researchers said that these new finds don't account for that racial disparity previously found in other studies, but it does highlight the importance of stroke prevention.

"As we search for the key drivers of the known disparities in cognitive [mental] decline between blacks and whites, we focus here on the role of 'health shocks' such as stroke," says study author Dr. Deborah Levine, an assistant professor in the University of Michigan medical school. "Although we found that stroke does not explain the difference, these results show the amount of cognitive aging that stroke brings on, and therefore the importance of stroke prevention to reduce the risk of cognitive decline."

According to the U.S. Centers for Disease Control and Prevention, strokes claim the lives of almost 130,000 Americans each year with more than 795,000 people in the United States suffering a stroke. Nearly one in four strokes occur in people who have suffered from a stroke before and it is estimated that it costs the health care system $34 billion each year.

Researchers that performed the survey at the University of Michigan recommend that everyone focus on stroke prevention. Some ways you can reduce your risk of stroke include controlling blood pressure and cholesterol, quitting smoking, increasing physical activity and controlling blood sugar if you suffer from diabetes.

Strokes can affect people of all ages. While they are more common and your risk of stroke goes up as you age, in 2009 34 percent of people hospitalized for stroke were younger than 65 years of age.